created & last_updated fields are missing from some REST API calls. Added missing fields to the following API calls
/api/dcim/virtual-chassis/
/api/dcim/cables/
/api/dcim/power-panels/
/api/dcim/rack-reservations/
/api/circuits/circuit-terminations/
/api/extras/webhooks/
/api/extras/custom-fields/
/api/extras/custom-links/
/api/extras/export-templates/
/api/extras/tags/